···6677## design
8899-- **direct PDS crawl** — the bootstrap relay (`bsky.network`) is called once at startup for the host list via `listHosts`, then all data flows directly from each PDS. no fan-out relay in between.
99+- **direct PDS crawl** — the bootstrap relay (`bsky.network`) is called once at startup for the host list via `listHosts`, then all data flows directly from each PDS.
10101111- **optimistic signature validation** — on signing key cache miss, the frame passes through immediately and the DID is queued for background resolution. the first commit from an unknown account is unvalidated; all subsequent commits are verified against the cached key. >99.9% cache hit rate after warmup.
1212···2424| `com.atproto.sync.getLatestCommit` | GET |
2525| `com.atproto.sync.listReposByCollection` | GET |
2626| `com.atproto.sync.listHosts` | GET |
2727+| `com.atproto.sync.getHostStatus` | GET |
2728| `com.atproto.sync.requestCrawl` | POST |
2828-2929-`getRepo` is not implemented — the relay does not serve full repository exports.
30293130## dependencies
3231